Code to add a Regex type to Meteor's EJSON

regex_ejson.js

import { EJSON } from 'meteor/ejson';

function getOptions(self) {
  const opts = [];
  if (self.global) opts.push('g');
  if (self.ignoreCase) opts.push('i');
  if (self.multiline) opts.push('m');
  return opts.join('');
}

RegExp.prototype.clone = function clone() {
  return new RegExp(this.source, getOptions(this));
};

RegExp.prototype.equals = function equals(other) {
  if (!(other instanceof RegExp)) return false;
  return EJSON.stringify(this) === EJSON.stringify(other);
};

RegExp.prototype.typeName = function typeName() {
  return 'RegExp';
};

RegExp.prototype.toJSONValue = function toJSONValue() {
  return { regex: this.source, options: getOptions(this) };
};

EJSON.addType('RegExp', value => new RegExp(value.regex, value.options));